/* Software License Agreement
 * 
 *     Copyright(C) 1994-2019 David Lindauer, (LADSoft)
 * 
 *     This file is part of the Orange C Compiler package.
 * 
 *     The Orange C Compiler package is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 * 
 *     The Orange C Compiler package is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 * 
 *     You should have received a copy of the GNU General Public License
 *     along with Orange C.  If not, see <http://www.gnu.org/licenses/>.
 * 
 *     As a special exception, if other files instantiate templates or
 *     use macros or inline functions from this file, or you compile
 *     this file and link it with other works to produce a work based
 *     on this file, this file does not by itself cause the resulting
 *     work to be covered by the GNU General Public License. However
 *     the source code for this file must still be made available in
 *     accordance with section (3) of the GNU General Public License.
 *     
 *     This exception does not invalidate any other reasons why a work
 *     based on this file might be covered by the GNU General Public
 *     License.
 * 
 *     contact information:
 *         email: TouchStone222@runbox.com <David Lindauer>
 * 
 */

#include <io.h>
#include <sys/types.h>
#include <errno.h>
ssize_t pread(int fd, void *buf, size_t nbyte, off_t offset)
{
  int save_errno;
  size_t result;
  off_t old_offset = lseek(fd, 0, SEEK_CUR);
  if (old_offset == (off_t)-1) return -1;
  if (lseek(fd, offset, SEEK_SET) == (off_t)-1) return -1;
  result = read(fd, buf, nbyte);
  save_errno = errno;
  if (lseek(fd, old_offset, SEEK_SET) == (off_t)-1) {
    if (result == -1) errno = save_errno;
    return -1;
  }
  errno = save_errno;
  return result;
}
